Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "Adding SDNVPN test cases to the Optional Test areas of the CVP."
  - Adding SDNVPN test cases to the Optional Test areas of the CVP.

    Included the tests for SDNVPN in the docetail scope document
    Performed spell checking of the committed test area document and included
    the section around test suite structure.  This patch should be reviewed
    and approved by the SDNVPN team prior to being merged.

    Change-Id: Ia2f9a1bddb02b9191da1239a73f121dce6687af1
    Co-Authored-By: Georg Kunz <georg.kunz@ericsson.com>
    Co-Authored-By: ChristopherPrice <christopher.price@ericsson.com>
    Signed-off-by: ChristopherPrice <christopher.price@ericsson.com>
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index df9fb1e..2c17036 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit df9fb1edfad233bd2ee0fb55e80a0a9d644b7742
+Subproject commit 2c170360711d8307ffab3fe8070a771650e4fd47